Campbell Scientific SR50A Distance Sensor - Manual (Page 30)

SR50A Sonic Ranging Sensor
The SR50A can be configured with either SDI-12, RS-232 or RS-485
communications. Shunt jumpers can be located on any of the 3 sets of
communication selection headers. All 3 jumpers should be placed only on one
group at a time. Never install more than 3 jumpers and never mix the jumpers
amongst the SDI-12, RS-232 or RS-485 locations.
The other jumper located on the SR50A places the sensor in either the normal
operation mode or in the Program update mode. The program mode is only
used for updating the internal firmware of the sensor. For operation the jumper
must be left in the RUN position.
Refer to Section 8 for SR50A Firmware Updates.
8. SR50A Firmware Updates
The firmware on the SR50A can be updated by using a terminal program such
as Hyperterminal. If your SR50A is configured for RS-232 communications,
the SR50A can be programmed from the I/O cable. The SR50A also contains
an internal female DB-9 connector.
Firmware updates should only be performed at an appropriate workstation with
static control procedures in place. Failure to follow the procedures may cause
damage to the sensor.
• Ensure that the SR50A is completely disconnected.
• Open the SR50A as follows:
o Remove the 6 slot head screws that are located on the bottom side of
the transducer housing.
o The transducer housing will separate from the main housing.
o Ensure that the screws and o-rings are kept and set aside.
o Disconnect the transducer housing assembly from the main body
assembly by pressing the tab on the connector and separating the
connector.
o Remove the 2 phillips screws from the bottom disk assembly.
o The bottom disk assembly should now separate from the main
housing.
o The circuit board will still remain connected to the housing via the
signal wires.
o Place the bottom disk/ circuit assembly on the work bench with the
circuit board and DB-9 connector facing up. Ensure that no part of
the PCB is in contact with the lid or other conductive objects.
• Move the jumper on the Run/Program Header from the Run position to the
Program position.
• Connect to the DB9 connector on the SR50A.
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